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Ordering Process and Dynamics of "Ceramics"

“陶瓷”订购流程及动态

基本信息

批准号：
05452063
负责人：
MATSUURA Motohiro
金额：
$ 4.67万
依托单位：
Kyoto Institute of Technology (KIT)
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

项目摘要

"Ceramics" are not only popular and familiar materials in our daily life but also essentialy important one for the modern frontier science and technology. Strucuturally, it is composed of grains of a single crystal which are strongly coupled to each other through an intermediary random surface. "Regularity" and "irregularity" coexist with different geometrical scales in such a material, the essense of which is characterized by a heterogeneous hierarchical structure. In order to study the ordering process, it is essential to examine the dynamical aspect of so called mesoscopic clusters of 10^<-2 3>A.We have, therefore, developed an high-sensitive observation system of nonlinear magnetic responses to an excitation AC field of a wide frequency range from sub-mili up to kiro Hz and of a wide range of amplitude variable from mili to kiro Oe. Then, we have applied it to oxide high-Tc superconductors, graphite intercalation compounds and so on and studied the ordering processes and the dynamical aspects. The experimental results on CoCl_2-GIC and NiCl_2-GIC revealed that nonlinear response is an efficient probe to investigate the nature of hierarchical successive transitions and the dynamical structure os intermediate phase in such "ceramics". In our study, the hierarchical superconductive transitions from intra-to inter-grain direction was first well distinguished separately. The nonlinear response was then found to show different singularitioes at these transition points. From the facts, nonlinear susceptibility has been proved to be an important probe which distinguishes a true superconductive glass from a so called gauge glass and thus to be an essential physical quantity to look after the nature of Josephson-type interactions or the microscopic origin of superconductivity.

“陶瓷”不仅是我们日常生活中常见的材料，而且是现代前沿科学技术的重要组成部分。在结构上，它由通过中间随机表面彼此强烈耦合的单晶颗粒组成。“规则”与“不规则”以不同的几何尺度共存于这种材料中，其本质特征是异质的等级结构。为了研究有序化过程，有必要研究10^ A的所谓介观团簇的动力学方面<-2 3>。因此，我们研制了一种高灵敏度的非线性磁响应观测系统，该系统对频率从亚毫赫兹到千赫兹，振幅从毫赫兹到千赫兹的宽范围的激励交流场进行非线性磁响应观测。然后，我们将其应用于氧化物高温超导体、石墨层间化合物等，研究了有序化过程和动力学方面。CoCl_2-GIC和NiCl_2-GIC的实验结果表明，非线性响应是研究这类“陶瓷”中分级连续相变本质和中间相动力学结构的有效探针。在我们的研究中，从晶粒内到晶粒间方向的分级相变首先被很好地分开。然后发现非线性响应在这些转变点处表现出不同的奇异性。事实证明，非线性极化率是区分真正的超导玻璃和所谓的规范玻璃的一个重要探针，是研究Josephson型相互作用的本质或超导电性的微观起源的一个基本物理量。